package stringTest;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: tao
 * Date: 2023-11-21
 * Time: 9:40
 */
public class Test3 {
    public static void main(String[] args) {
        String s1 = "hello";
        String s2 = "HELLO";
        //小写转大写
        System.out.println(s1.toUpperCase());
        //大写转小写
        System.out.println(s2.toLowerCase());
    }
}
